McGuire is a determined, loyal, and passionate member of the USS Pennsylvania. He is horrified when the outbreak begins and witnesses the deaths of many of his crewmates. When faced with the decision to fire a nuke at Chicago, he goes against it, firmly stating that he refuses to fire on his own country.
Nothing is known about McGuire's life prior to or as the outbreak began, except that he worked as a lieutenant aboard the USS Pennsylvania.
McGuire stands near the outer hatch with Riley, Pierce, and Alvarez. The four men discuss how, despite the fact that they're currently only 50 klicks off of Galveston, they can't reach anyone. Pierce reveals that after being silent on every means of communication, NC2 suddenly picked up an incomplete message a half an hour before. When Riley asks what he means, Pierce tells him that it was "incomplete like they hit send without finishing the damn thing." Pierce tells the others that he has also picked up an FM broadcast out of Houston revealing that the Army has been deployed. McGuire is surprised that it's the Army and not the National Guard and Pierce explains that the broadcast talks about the Army being deployed for "medical incidents." Riley recognizes that the partial EAM and the Army being deployed can't be a coincidence. McGuire worries about his sister in Houston while Pierce tells the others that Riley has a son that he hasn't even seen yet. Pierce suggests that with how close to shore they are, they should consider going for a swim. McGuire realizes that Pierce is suggesting that they abandon ship and their duties, but Riley states that no one is doing that. McGuire chuckles when Pierce jokingly calls Alvarez miserable. Just then an announcement is made over the PA about ice cream sundaes in the cafeteria. McGuire goes to the mess hall with the others.
As Riley gets attacked by a zombified Voss, McGuire drops a wrench on Voss, putting him down. Riley and Alvarez climb up the ladder to join McGuire. Reaching the silo hall, Riley opens the hatch and tells his companions that the weapons' room is on the other end of the hall. However, it is filled with walkers. The three sneak through the hall as walker growls and screams echo around them. Suddenly, Farley emerges, startling Alvarez into accidentally shooting and killing him. McGuire holds Farley in his arms asking Alvarez what he has done. Panicking, Alvarez tries to leave through a nearby hatch against Riley's orders not to open it, but walkers enter through the hatch and attack Alvarez, causing Alvarez to commit suicide. Reaching the end of the hall, McGuire and Riley are joined by Pierce and Captain Renwick who are still alive.
The four men enter the weapon's room, where Renwick points his gun at Riley, Pierce, and McGuire, telling them to show their arms to see if they were bitten. No one is shown to be bitten much to Renwick's relief. McGuire proceeds to list many fallen crewmates. The four men realize that they now have their answer as to why they were taken off of the NATO run and the medevac wasn't sent for Friedman. Renwick believes that the Pennsylvania must be all that's left, but McGuire and Pierce aren't convinced. McGuire angrily says that there are a hundred men out there eating each other alive, and that it matters to him. Renwick states that they have plans in place for this sort of thing and Riley suggests that for all they know, the missile they've been ordered to fire could stop it. Renwick agrees with Riley and tells Pierce and McGuire that firing the missile is all that matters now. A new message comes through which Riley, McGuire and, reluctantly, Pierce agree is authentic. The launch coordinates print out and after reading them, Renwick tells his men that the target is Chicago and he orders them to prepare to launch.
As Captain Renwick orders him to prepare to launch, Riley hesitates, pointing out that they would be firing on their own country. Riley ultimately decides to not to fire the missile. Renwick orders Pierce to take the key from Riley, who refuses. He then orders McGuire to take the key from Riley, but he also refuses, stating he will not fire on his own country. Renwick calls their actions mutiny and threatens to have them all court martialed, but McGuire states that their orders are comparable to Nuremburg and Riley tells him that Renwick's superior orders are cruel and war crimes. Renwick suddenly collapses to his knees. McGuire notices that Renwick has been bitten. Renwick expresses hope that the three are right about not launching the nuke. McGuire watches as Riley mercy kills the dying Renwick with a headshot.
Putting the gun down, Riley tells McGuire and Pierce that they are going to get out of here. Putting on Renwick's key, Riley addresses the crew over the PA system, informing them that Captain Renwick is dead and that they have a new mission: "get this ship topside. Go home."
McGuire hands Riley and Pierce a pipe and a sharpened shaft of metal, the only weapons that he could find which Pierce calls better than nothing. McGuire readies himself with his wrench as Riley is about to open the hatch. Just then, Walter contacts Riley over the sub's comms, revealing that a group had made it to the bridge, but they are now stuck there with too many walkers outside. Getting an idea, Riley asks if Walter has ever pulled a chicken switch and, laughing, Walter orders them to hold on tight. As McGuire, Riley, and Pierce brace themselves, Walter announces an emergency blow over the comms and then blows the sub's ballast tanks, rapidly sending it to the surface and throwing the swarming walkers around and to the ground.
With the sub on its way to the surface and the walkers incapacitated for now, McGuire, Riley, and Pierce rush through the hatch and the hallway, safely reaching the other end. McGuire safely enters the outer hatch. When Riley enters, McGuire notices Pierce is missing and asks where he is, to which Riley shakes his head, signifying he didn't make it. Riley tries to give the second key to McGuire, but he tells Riley that he doesn't want it and instead gives it to Walter. Riley tells his remaining crew that it's been an honor to serve with all of them and now they have to go find their families which is all that they have left. Riley gives the order to abandon ship and the eight survivors of the USS Pennsylvania climb out of the hatch to the surface. McGuire tells Riley everyone is out, before climbing out himself.
This list shows the victims McGuire has killed:
- Voss (Zombified)
- Possibly many enemy combatants (Pre-Apocalypse)
- Possibly numerous counts of zombies
|The Althea Tapes|
|Dead in the Water||✔||✔||✔||✔|
|✔||Appears||✔||Voice is heard|
|👁||Appears with no lines||✔||Appears in a flashback|
|✔||Appears as a walker||🖼||Appears in a photograph/video|
|✔||Appears as a corpse||✔||Appears in a hallucination/dream|